The present invention relates to musical instrument training devices, particularly for stringed instruments and more particularly to an improved fret board training device that includes a matrix of thin lights displayed within the fret board, consisting of a light matrix of electroluminescent flat panel displays which are viewable from a wide angle and under ambient lighting conditions wherein the electroluminescent display (or "ELD") uses a layer of phosphor material and electrode layers with the electrodes supplying an electric field across the phosphor layer.
There are a number of different stringed instruments which have a larger sound box or body with a long narrow neck attached thereto and include a plurality of, for example, 6-12 strings and a number of frets or transverse raised ribs across the neck at regularly spaced intervals. Such instruments are, for example, the guitar, banjo, and the like.
The guitar is typically played by depressing one or more of the strings at certain locations between the frets to shorten the string and thus produce various sounds that are pleasing to the listener. Thus, a user must be able to visually locate a particular and precise fret and string location on the instrument and correctly depress that string at that fret position to produce a particular musical chord or note.
Learning to play the guitar means learning the particular locations for strings and frets as well as an ability to quickly and easily depress the proper string location. The guitar is unmarked with any indicia that would be a clue to the student, thus the learning process is difficult without some visual aid.
One solution to this problem has been to provide a booklet having a diagram corresponding to the guitar chord positions so that the student can look at the book and then visually place his or her fingers at the particular location on the instrument that corresponds to a particular chord or note. This particular practice of teaching is awkward and cumbersome because the student must repeatedly change the position of his head in order to look at either the guitar or the booklet having the instructions. This problem has been discussed in previous U.S. patents, for example, U.S. Pat. No. 4,286,495 issued to John Roof and entitled "Musical Instrument Training Device." The Roof '495 patent offers a possible solution to the above-described problems by providing an electrical device which helps train a student to play a stringed instrument and includes a group of visual indicators mounted on the neck of a fret board and each indicator being immediately beneath and in registry with a particular string and fret of the instrument so as to identify therewith. The Roof '495 patent further provides a second group or plurality of visual indicators mounted on the fret board adjacent the sounding hole in spaced relationship to the first plurality of visual indicators and each one is associated with a particular string to be strummed for a particular musical chord. Switches are provided for selection of musical chords and are operably connected to a diode matrix for energizing selected ones of the visual indicators in the first and second groups whereby the energized visual indicator pattern of the first group represents finger placement loctions along the neck of the fret board for a selected musical chord and the energized visual indicator pattern or the second group represents appropriate strings to be strummed associated with the selected musical chord.
The Roof '495 patent uses light emitting diodes or LEDs which cannot be visualized unless the line of sight is at or very close to a line perpendicular to the plane of the viewing surface. This is a particular problem with guitar players because the guitar is usually placed against the body of the musician. The front surface of the guitar as well as the front face of the fret board is directed away from the musician as well as away from the musician's eyes. Thus, normally the musician must bend over only slightly in order to see the fret board. Nonetheless, the fret board is normally viewed at wide angles to an imaginary line perpendicular to the plane of the viewing surface (e.g., 60-80 degrees). This necessitates a total accessible viewing angle up to 160 degrees. Otherwise, the guitar player would need to lay the guitar virtually flat against his or her lap or against a table in order to see the light display which would be an uncomfortable and unnatural position considerably hindering the playability of the instrument.
Several other patents have been issued which are directed to the problem of a visual device for teaching the playing of a musical stringed instrument. Examples of other patents include the Pipkin U.S. Pat. Nos. 2,788,699, the Sapinski 3,854,370, the Johnson 3,978,757, the Gilbert 3,943,815, the Ratanangsu 4,080,867, and the Habicht 4,545,281.
These patents do not solve the problem of providing an easily viewable matrix of thin lights displayed within the fret board of a guitar and having a wide angle viewing area under ambient lighting conditions.
Electroluminescent displays (ELDs) are commercially available. ELDs are discussed, for example, in the March 1985 issue of BYTE magazine with appended bibliography and references.